Self-steering system

ABSTRACT

The present invention relates to a self-steering system that permits a boat to stay on a set course relative to an apparent wind; and to do so, the system uses a wind vane that pivots to undergo angular displacements. The resultant angular displacement of the wind vane is transmitted to a servo-tab of a rudder, the servo-tab in turn undergoing a corresponding angular displacement; so that the new rudder orientation varies the boat heading. The self-steering system further comprises a clutch for engaging and disengaging the system while setting a new course. The system also comprises means for raising the rudder out of the water.

[11] 3,826,213 July 30, 1974 SELF-STEERING SYSTEM [76] Inventor: Reinhold W. Riebandt, Box 2153,

ldyllwild, Calif. 92349 22 Filed: June 15, 1971 21 Appl. No.: 153,248

[52] US. Cl 114/144 C [51] Int. Cl B63h 25/52 [58] Field of Search 114/144 C, 144 A, 144 R,

[56] References Cited UNITED STATES PATENTS 1.681.415 8/1928 Lec 114/144 C 3,180,298 4/1965 Gianoli 114/144 C 3.678.878 7/1972 Ross-Clunis 114/144 R FOREIGN PATENTS OR APPLICATIONS 857,852 111961 Great Britain 114/144;144 C 230,471 8/1967 U.S.S.R 73/188 Primary Examiner-George E. A. Halvosa Assistant Examiner-Sherman D. Basinger Attorney, Agent, or Firm-Harvey C. Nienow [57] ABSTRACT The present invention relates to a self-steering system that permits a boat to stay on a set course relative to an apparent wind; and to do so, the system uses a wind vane that pivots to undergo angular displacements. The resultant angular displacement of the wind vane is transmitted to a servo-tab of a rudder, the servo-tab in turn undergoing a corresponding angular displacement; so that the new rudder orientation varies the boat heading. The self-steering system further comprises a clutch for engaging and disengaging the system while setting a new course. The system also comprises means for raising the rudder out of the water.

11 Claims, 11 Drawing Figures Pmmmm 3,826,213

sum 2 or 2 INVENTOR.

i fw

kg/NHOLD I. Ewan/v07.

SELF-STEERING SYSTEM BACKGROUND In the sailing of boats, it is practically essential for a helmsman to be in constant attendance, regardless of the sea or weather conditions; because there is always a tendency for the boat to deviate from its set course due to wave action, underwater currents, and other water movements. As a result, if there were no helmsman in attendance the boat would tend to wander off course.

However, the need for a constant helmsman increases the size of the crew by about one person-and on long trips, the requirements in terms of food, water, facilities, etc., is quite large; and elimination of these would appreciably decrease the weight that must be carried on board the boat.

It therefore becomes extremely desirable to have a system that can take over the steering duties; and many such so-called self-steering systems have been proposed. Unfortunately, none of themhave proved completely satisfactory.

OBJECTS AND DRAWINGS It is therefore the principal object of the present invention to provide an improved self-steering system.

It is another object of the present invention to provide an improved wind operated self-steering system.

It is a further object of the present invention to provide an improved self-steering system that is extremely simple to operate.

It is a further object of the present invention to provide an improved self-steering system that has minimal oscillation characteristics.

It is a still further object of the present invention to provide an improved self-steering system that has a rapid response.

The attainment of these objects and others will be realized from a study of the following description, taken into conjunction with the drawings of which FIG. 1 is an overall view of the self-steering system;

FIG. 2 is an overall view of the self-steering system, with the rudder folded so that it is out of water;

FIG. 3 is a top view of the system of FIG. 1;

FIG. 4 is a longitudinal cross-sectional view of the overall system;

FIG. 5 is a cross-sectional view showing the clutch";

FIG. 6 is another cross-sectional view showing the overall operation of the clutch;

FIG. 7 is a view of the secondary rudder;

FIG. 8 is a view of the self-righting apparatus;

FIG. 9 is a view of the hinging operation;

FIG. 10 is a view of an arrangement that bypasses the self-righting mechanism; and

FIG. 11 is a view of a clutch for operating the apparatus of FIG. 10.

SYNOPSIS Broadly speaking, the disclosed self-steering system comprises a wind vane that does not have a dead angle, so that the self-steering system is extremely sensitive. The disclosure also describes how the wind vane is kept vertical to minimize undesired effects when the boat heels. A transmission is used for transmitting the angular displacement of the windvane to a servo-tub of the rudder; the transmission comprising a clutch for engaging and disengaging the system. The rudder is designed so that the wind powered wind vane produces an angular displacement of only the servo-tab; the body of the rudder being actually pivoted by water pressure produced by the servo-tab angular displacement; so that a minimum amount of wind power is needed for the operation of the system.

DESCRIPTION Self-steering has been defined as the ability of a boat to stay on a set course relative to the apparent wind." The broad outlines of the disclosed self-steering system for achieving this result are illustrated in FIG. 1, the details being reserved for other illustrations and for later explanation. In FIG. 1, a boat 10 has a standard rudder 1 1 that is operated by a tiller arrangement (not shown) to set the desired course of the boat 10. As indicated above, a helmsman must ordinarily remain in attendance to offset the changes in course.

Basic Theory The disclosed self-steering system removes the necessity for a constant attendance of the helmsman; and operates as follows. A hollow, symmetrical, wedge-shaped wind vane 12 has a longitudinal pivot arrangement, such as a vane axle 13, that permits the wind vane 12 to pivot about its folded edge 14. Wind vane 12 has a counterweight 15. The vane axle 13 fits into suitable bearings of a weighted pendulous shaft 16 that, in turn, is attached to the upper portion 18a of a housing 18; housing 18 being affixed, as by brackets 19 and 20, to the boat 10.

In a manner that will be discussed more fully later, course deviations produce angular displacements of wind vane 12, and these angular displacements are transmitted to a servo-tab 21 of a three part secondary rudder 22.

The net effect is that whenever a course deviation occurs, the wind vane 12 undergoes an angular displacement relative to the boat; this wind vane angular displacement being transmitted to the secondary rudder 22, this secondary rudder then moves in such a direction as to compensate for the course deviation. In this way, the disclosed self-steering system permits the boat to stay on its set course.

The foregoing explanation has indicated that the boat is to have a main rudder 11 and a secondary rudder 22; and that the disclosed concept is to act upon the secondary rudder 22 with the main rudder immobilized, as by lashing down its tiller, to provide improved lateral stability. The reason for this arrangement is to permit the disclosed self-steering system to be retro-fitted to an existent boat.

However, the disclosed self-steering system may be such as to act upon the main rudder of a boat in those cases where a new main rudder or a new boat is designed for this purpose. This will become apparent from the following discussion.

System Disablement Under some conditions, it may be desired to disable the self-steering systems; and one way of achieving this result is to remove the submerged portion of the secondary rudder bodily from the water. It will be seen, from FIG. 1, that the lower portion 18b of housing 18 is hinged at hinge 24; and FIG. 2 indicates that the submerged portion of the secondary rudder 22 may be pivoted upwardly to remove it from the water. As indicated in FIG. 2, this result may be achieved by releasing the threaded locking shaft 23, and, by using a line attached to a portion of the secondary rudder 22, to raise the secondary rudder 22 out of the water.

In this way, rudder 22 may be raised out of the water for servicing, etc.; and also for those racing events that ban the use of a self-steering system.

FIG. 3 shows a top view of the apparatus taken as indicated in FIG. 1; FIG. 3 showing, among other features, the vane axle 13, the pendulous shaft 16, the upper housing portion 18a, the upper bracket 19, and the locking screw 23.

Gimballing Arrangement Attention is now directed to FIG. 4, which shows a longitudinal cross-section of the disclosed apparatus. It will be noted that the vane axle 13 is rotatably and longitudinally coupled by means of suitable hearings in pendulous shaft 16, for providing co-axial rotation; and that pendulous shaft 16 has an elbow portion 25 that is tubular in cross-section, and is so positioned and journalled in housing 18a that the pendulousity causes elbow 25 to rotate horizontally in the upper housing portion 180. A snubbing thumb screw 26 acts through a snubber 27 as a locking member or as a brake, depending upon conditions. The functioning of the pendulous shaft 16 and the snubbing arrangement will be discussed later.

Transmission Referring back to FIG. 1, it will be recalled that wind vane 12 undergoes an angular displacement with course deviations, thus producing angular movement of the vane axle 13 within the pendulous shaft 16. FIG. 4 indicates that the pulley 28 is affixed to vane axle 13, so that as the vane axle 13 pivots, the pulley 28 pivots a corresponding amount.

A belt 29 fits around the first pulley 28 and around a second pulley 30 positioned in the upper housing portion 18a; pulley 30 being affixed to a transmission shaft 32, so that the transmission shaft 32 undergoes an an gular displacement corresponding to the angular displacement of the wind vane 12.

FIG. is a cross sectional view taken as indicated to illustrate the relation between the vane axle 13, the pendulous shaft 16, the upper housing portion 18a, the elbow 25, the snubbing screw 26, the snubber 27, the pulley 28, and the belt 29.

The cross-sectional view of FIG. 6 shows, among other elements, the pulley 28/belt 29/pulley 30 arrangement, the elbow portion 25, the upper housing portion 180, the upper bracket 19, and the locking screw 23.

Returning now to FIG. 4, the transmission shaft 32 in housing 18 is connected at its lower end (in a manner to be explained later) through a drive pin 31 to a crank arm 33 that is best seen in the solid line representation of FIG. 7. As indicated the crank arm 33 is connected to a push rod 34 that has the other end connected to a second crank arm 35; this in turn being connected to the pivot shaft 38 of the servo-tab 21.

The overall operation of the transmission may be understood from FIGS. 4, 6 and 7. When a course deviation occurs, it causes the wind vane 12 and its vane axle 13 of FIG. 4 to undergo an angular displacement (say a clockwise angular displacement as indicated by the curved leftmost arrow 36 of FIG. 6). This clockwise angular displacement is transmitted through pulley 28, through the action of belt 29, through pulley 30,

through transmission shaft 32, to the first crank arm 33 of FIG. 7, through push rod 34, through the second crank arm 35, to the pivot'shaft 38; and thus to the servo-tab 21 which thereupon undergoes a clockwise displacement. The effect on linkage 33, 34, 35 and on servo-tab 21 is indicated by the dotted line representation of FIG. 7.

Thus, the servo-tab undergoes an angular displacement that is the same clockwise direction as the angular displacement of the wind vane; the amount of servo-tab angular displacement being primarily a function of the pulley diameters, although the magnitude of the servotab angular displacement may be controlled by adjusting any of the above described transmission linkages. Typically, the ratio between the wind vane angular displacement and the servo-tab angular displacement is about 0.8 to 1.0.

Thus, a course deviation, acting through the wind vane and the transmission, produces an angular displacement of the servo-tab 21; and the effect of the servo-tab angular displacement may be understood from the following discussion.

Course Deviation Compensation It will be noted, from FIGS. 1, 2 and 7, that the secondary rudder 22 comprises three parts: a nose 40, a body 41, and a servo-tab 21. Referring specifically to FIG. 7, the solid line representation shows these three rudder parts aligned.

The above described course deviation has caused a movement of the secondary rudder linkage, and a corresponding angular displacement of the servo-tab 21, these being shown in the dotted line representation of FIG. 7.

Since the boat is moving through the water, the underwater waterflow pattern now exerts a greater pressure (see FIG. 7) on the exposed surface 45 of the angled servo-tab 21 than on its shadowed surface 46. However, servo-tab 21 cannot because of wind pressure on wind vane 12 pivot back into a streamlined configuration with the rest of the secondary rudder 22;

and the resultant water pressure on the exposed surface 45 of servo-tab 21 causes the body portion 41 of the secondary rudder 22 to now pivot around its own pivot axis 47 of FIG. 4. Therefore, the secondary rudder 22 now takes the orientation shown in the dashed line representation of FIG. 7.

It will be apparent that the new orientation of the secondary rudder 22 is such that the boat compensating for the course deviation; and is approaching its original heading. All this has been accomplished by the disclosed self-steering system, without any attention on the part of the helmsman.

As other slight course deviations take place, in either direction, the disclosed apparatus makes corresponding adjustments to the boat heading. It will be noted that the servo-tab 21 always pivots in the same direction as the wind vane 11, and that the body 41 of the secondary rudder 22 always pivots in the opposite direction.

It should be realized, at this point, that the wind vane 12 does not turn the body of 41 of the secondary rudder 22; the wind powered wind vane merely turns the relatively small servo-tab 21, and the waterflow pressure then turns the body portion 41 of the secondary rudder 22. Thus, the disclosed concept minimizes the amount of power that the wind vane has to develop to the extent of the previously discussed wind vane/servotab angular displacement ratio.

The foregoing explanation has been presented in terms of a retrofit self-steering system; that, is, in terms of a secondary rudder that can be fitted to a boat that already has a main rudder. However, as indicated above, the self-steering system may actually be built into the trailing edge of the boats keel.

Alternatively, the trailing edge of the keel may be revised to act as the nose of a three part rudder having a nose portion, a body portion, and a servo-tab; and this trim tab may now be linked, not to a wind vane as discussed above, but to the tiller. Under this condition, the force necessary to move the tiller is reduced drastically, since the tiller force now pivots only the servo-tab. The actual force for moving the rudder body is now obtained from the waterflow pattern, as explained above.

The Clutch There are times, to be discussed later, when it is desirable to couple or to uncouple the wind-vane 12 from the servo-tab 21, and many types of clutch may be used for this purpose; the disclosed belt/pulley arrangement lends itself to a particularly desirable clutch arrangement.

It will be noted that FIGS. 1, 2 and 4 illustrate a handle 50, and the function of this handle is as follows. Referring back to FIG. 4, it will be recalled that the foregoing discussion has assumed that belt 29 was tight on pulleys 28 and 30; and under those conditions the system operates as described.

When handle 50 is raised, the locking cam 51 pivots arounds its pivot and falls to hanging orientation. At this time, the handle 50 may be pushed-leftward, and this movement causes the longitudinal element 52 to also move to the left, a pivot type direction changing arrangement 53 moving a sliding collar 54 to the right. Sliding collar 54 is affixed to a strap 55 of elbow portion 25, so that the entire elbow portion 25 also moves to the right. Since the pendulous shaft 16 is affixed to elbow portion 25, shaft 16 also moves to the right, car.- rying with it the pulley 28. This rightward movement of pulley 28 immediately loosens the belt 29, thus uncoupling the wind-vane 12 from the servo-tab 21. In this way, the clutch handle 50 separates the input and the output of the transmission.

Setting Up the Self-Steering System The system is set up by first uncoupling it by means of the above-described clutch; with the self-steering system thus uncoupled, the boat is given the desired heading by means of the boats main rudder 11. Tne now-uncoupled wind-vane 12 orients itself to a neutral angle relative to the apparent wind, and the nowuncoupled parts of the secondary rudder 22 align themselves to a neutral orientation relative to the underwater waterflow pattern. Once these conditions have been achieved, the self-steering system is engaged by pushing in on handle 50, and by raising the locking cam 51 to the illustrated position to maintain the engaged relationship. Now that the self-steering system is fully engaged, it is ready to operate in the above-described manner.

In the disclosed self-steering system, the areas of the movable portions of the secondary rudder 22 are quite small in comparison to the area of the main rudder l1, and their effect can be easily overridden by the main rudder 11. Even if the self steering system is left engaged during an urgent correction of the boats heading, its effect during this maneuver is relatively small, and will not affect the handling of the boat.

The belt type clutch has an additional advantage as follows. It will be recalled that the self steering system is to be uncoupled for the purpose of establishing the boats desired heading, and is then to be recoupled. Since in the described puIley/belt/pulley system, the coupling actually occurs between the belt and the two pulleys; recoupling can take place at any point on thier surfaces, thus providing exactly the desired neutral wind vane/servo-tab relationship.

Gimbal Effect It will be recalled that the previous discussion indicated that the wind vane 12 was mounted in the bearings positioned in the pendulous shaft 16 and that the pendulous shaft 16 had an elbow portion 25 that permitted it to rotate horizontally. The reason for this structure will be understood from the following discusson.

It is of course well known that every boat can heel (roll from side to side) as much as 50", under the action of a wind. As the boat heels over sharply, the wind vane 12 tends to assume a horizontal orientation, rather than the desired vertical orientation; and this new orientation impairs the effectiveness of its operation; and, furthermore, may produce extremely undesirable rudder effects in this orientation.

In order to maintain maximum effectiveness when the boat heels, the wind vane 12 must be able to be uncoupled; or, preferably, be mounted-in a self righting manner. In order to achieve the latter results, (see FIG.

4) the pendulous shaft 16 is weighted as indicated at l7, and the elbow portion 25 of the pendulous shaft 16 is able to pivot horizontally in the upper portion 18a of the housing. The result of this structure is that, as the boat heels, the pendulous shaft 16, the wind vane axle l3, and the wind vane 12 all remain substantially vertical at all times; whereas the housing 18, which is affixed to the boat, may assume different vertical angles as the boat heels. It should be noted that the belt 29 has enough inherent resiliency to permit the described gimballing effect, while still permitting the transmission of wind vane angular displacements.

FIG. 8 shows how the pendulous shaft 16 and the vane axle 13 remain vertical, while housing 18 and the upper housing portion 18a are shown to assume various angles as the boat heels.

While the elbow portion 25 rotates in the upper housing portion 18a, it may be desirable at times to prevent or limit this pendulous rotation action, and this result may be achieved by use of a snubbing screw 26 of FIGS. 4 and 5. If this screw is tightened securely it locks snubber 27 against the elbow 25, thus preventing the pendulous movement. Alternatively, snubbing screw 26 may be somewhat looser, but still a snug fit; whereupon it merely snugs the pendulous movements.

In those cases where the pendulous effect is not desired, the construction may be simplified as indicated in FIG. 10. Here vane axle 13 is rotatably coupled to the transmission shaft 32, these being held together by a quick acting coupling/uncoupling clamp means such as 57 shown in FIG. 11.

The Wind Vane In order to obtain maximal effectiveness from the wind vane 12, it is preferably formed into a hollow symmetrical wedge like configuration of suitable size, typically about 3 feet high, about 1 /2 feet long, and having an included angle of about 22. It has been found that a wind vane of this general size and configuration develops sufficient force to turn the disclosed servo-tab 21.

The wind vane has the following advantages: When positioned in any wind at all, each side of the wind vane develops a turning torque; the two torques being equal in magnitude, and opposite in direction, and thus negating each other. As soon as a course deviation occurs, the wind vane tends to rotate in relation to the boat, retaining its original direction into the wind. However, the wind vane is linked to the servo-tab by the described transmission; so that the servo-tab did not follow the course deviation of the boat. The servotab has the same direction in relation to the wind vane as it had before the course deviation took place, al though the servo-tab now has a different direction relative to the boat. Now the water pressure on the exposed surface of the servo-tab applies a counter force thru its linkage to the body of the secondary rudder, and this brings the boat back to its original heading. The wedge shape vane, due to its built-in angles of attack, has a sensitive design that assures that there is no dead angle within which the self steering system is inoperative.

It was indicated above that the disclosed self-steering system responds very quickly to the small course deviations, but it should be noted that a change of the wind strength (wind velocity) has no effect. The reason for this will be understood by referring back to FIG. 1. Since the wind vane is symmetrical and has divergent surfaces, a given wind velocity causes each side of the wind vane to produce equal and opposite torques. If the wind strength increases, or decreases, the two surfaces of the wind vane still produce equal and opposite torques, although the torques may be larger or smaller than they were previously. Since the wind vane pivots only in response to differences in torque, the equal torques resulting from the change of wind velocity will not cause any pivoting effect of the wind vane. Therefore, the wind vane is substantially immune to changes in wind velocity.

The disclosed wind vane has another feature of interest. Basically, it is a hollow wedge shaped configuration that is most readily achieved by stretching a piece of canvas over a frame. However, in extremely stiff winds, the exposed area of the canvas may cause it to subject the vane structure to dangerously high breaking forces. The disclosed concept is such that the canvas covering the vane structure may be removed to expose small canvas support arms 58 of FIG. 2 that now provide sufficient area to produce the desired wind vane effect in a stiffer wind.

The Trim Tab One of the novelty features that makes the disclosed self-steering system so effective is that the servo-tab 21 requires very little power to move it. This is accomplished by the following techniques. It will be noted, from FIG. 7, that the disclosed servo-tab 21 has an unusual cross-sectional configuration, in that its crosssection is substantially a symmetrical isosceles triangle wherein the base of the triangle is the trailing edge, and has a concave configuration; and more particularly, the concavity is formed of flat, angled, planar surfaces that are also symmetrical. It has been found that the disclosed concavity is extremely effective in eliminating the formation of disturbing vortexes behind the secondary rudder 22 as the rudder moves through the water. Since vortexing wastes power, the anti-vortexing configuration is one of the main reasons that the disclosed apparatus operates so well.

The servo-tab, like the wind vane, has an effectiveness that is largely due to its not having a dead angle for similar reasons to those discussed above.

In addition, it has been found that by extending both the upper end of servo-tab 21, and the upper end of the secondary rudder body 41 so that they are both above water level, as indicated in FIG. 1, these extensions eliminate vertical vortexing as the secondary rudder 22 moves through the water. Here again, the antivortexing features minimizes the loss of power, and permits even further improved operations.

The push rod 34 and its crank arms 33 and 35 for pivoting the servo-tab 21 are illustrated in FIG. 1 as being above the water level; but it has been found advantageous to enclose them in a housing (not shown) to eliminate contact with water spray, waves and the like. This also minimizes theloss of power.

It is known that a large servo-tab will require more wind-vane power to pivot it; and it is also known that if the servo-tab is too deep in the water, the increasd water pressure will also require more wind generated power to pivot the servo-tab. Therefore, in the disclosed self-steering system, the servo-tab 21 is located near the surface of the water, and is made of a suitable size to provide the desired compensation in a reasonable time interval, in view of the size of the wind vane and the boat. Typically, the servo-tab 21 may be about 6 inches long, may have a height equal to about onethird of the height of the secondary rudder 22, and may have an included angle of about 13. As suggested above, the interrelationship between the wind vane 12 and the servo-tab 21 depend upon the size of the wind vane, the ratio of the pulley diameters, the proportions of the crank arm mechanism, the area, shape and location of the servo-tab, etc. All of these may be varied to maximize them for a particular boat.

Stability In a self-steering system such as that disclosed it might be expected that a certain amount of oscillation would occur, but the disclosed system has practically no oscillation at all. One of the principal reasons for the lack of oscillation is as follows.

Ordinarily, a course deviation will cause the apparatus to react as discussed above; but in most mechanisms, there is a tendency to overshoot, and these overshoots result in oscillation. In the disclosed system it will be noted that the secondary rudder 22 of FIG. 7 has a rigid water cutting nose 40 of appreciable length. Moreover, nose 40 is formed of laminate (hardwood, plastic, epoxy, etc.) that is not only very strong, but is also quite resilient. Therefore, nose 40 may be slightly flexible, thus helping to dampen out vibrations which might cause fatigue to the other parts of the structure. Additionally the rigidly mounted nose introduces a stabilizing effect on the boat by being mounted to the vessel far aft of the dynamic center of the underwater part of the boat; and it also controls and equalizes the water flow to the rudder body and servo-tab, and thus contributes to the effectiveness of the servotab creating pressure for rudder turning.

Hinge Mechanism lt was point out above that the secondary rudder 22 may be lifted out of the water by loosening locking shaft 23, and letting the housing 18 break-away at hinge pin 24 of FIG. 4. This hinging action, of course, requires that the transmission shaft 32 be disengageable from crank arm 33; and while there are a number of structures that will permit this, the following has been found to be extremely simple and effective. As indicated in FIGS. 4 and 9, transmission shaft 32 terminates in a plastic insert 60 that is force fitted into the open end of the transmission shaft 32, the plastic insert 60 having a suitably shaped groove that receives a tongue-like termination 61 of drive pin 31. In this way, when the housing is open at hinge 24, the tongue 61 merely slips out of the groove thus permitting easy hinging. When it is decided to re-engage the lower portion of housing 18, the tongue 61 easily slides back into the groove, and the mechanism is ready for duty.

SUMMARY The disclosed wind powered self-steering system has many advantages that are important to the boat owner. First of all, the system is extremely simple to operate. Second, the system is very sensitive to small course deviations. Third, the system responds immediately, because the vane and servo-tab do not have dead angles. Fourth, the system operates efficiently because most of the power needed for rudder movement is derived, not from the wind,'but from the undersurface waterflow pattern. Fifth, the wind vane has an inherent construction that permits it to be easily converted for use in stiff wind. Sixth, the system may have an arrangement for maintaining the wind vane in a substantially vertical orientation, in spite of the heeling of the boat. Seventh, a quick acting clutch is available for those times when it is necessary to disengage the system. Eighth, the submerged portion of the secondary rudder may be raised bodily out of the water when so desired. Ninth, the servo-tab is of an anti-bortexing design. Tenth, the secondary rudder is placed in such a manner that it minimizes vertical vortexing. And finally, the disclosed self steering system has proved itself in many cruises.

What is claimed is:

l. A self-steering system for a boat, comprising;

a hollow symmetrical wedge shaped wind vane mounted on said boat, said wind vane adapted to undergo angular displacements;

a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder;

transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab;

clutch means for engaging and disengaging said wind vane and said rudder;

means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat;

whereby the power for pivoting said body portion to said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.

2. The combination of claim 1 wherein said servo-tab and said body portion of said rudder are positioned with their upper ends slightly above the water level.

3. The combination of claim 1 wherein said transmission means comprises a first clutch element adapted to pivot with said wind-vane, and further comprises a second clutch element adapted to engage said servo-tab.

4. A self-steering system for a boat, comprising:

a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements;

said wind vane being of a hollow symmetrical wedge shape, having a frame and cover therefor, said frame having a plurality of normally hidden perma- I nent arms that can be exposed to a stiff wind by removing said cover from said frame;

a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder;

transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab;

means for causing the underwater waterflowpattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat;

whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.

5. A self-steering system for a boat, comprising:

a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements;

a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted at its leading edge to said body portion of said rudder;

said servo-tab having a substantially wedge shaped cross-section so as to increase in width from its leading to its trailing edge;

transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab;

means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat;

whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.

6. A self-steering system for a boat, comprising:

a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements;

a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder;

transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab;

said transmission means comprising a pulley adapted to pivot with said wind vane, and further comprising a belt adapted to engage said pulley;

said transmission means further comprising clutch means for engaging and disengaging said pulley/- belt arrangement;

means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat; 7

whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.

7. A self-steering system for a boat comprising:

a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements;

gimballing means for causing said wind vane to maintain a substantially vertical orientation;

a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted at its leading edge to said body portion of said rudder; said servo-tab having a substantially wedge shaped cross-section so as to increase in width from its leading to its trailing edge;

transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab;

means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat;

whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.

8. The combination of claim 7 wherein said gimballing means comprises a weighted pendulous shaft adapted to maintain a substantially vertical orientation, and said wind-vane is adapted to remain in alignment with said pendulous shaft.

9. A self-steering system for a boat, comprising:

a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements;

a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder;

transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab;

means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased'water pressure to pivot said body portion of said rudder relative to said boat;

whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane;

means for removing the normally submerged portion of said rudder from the water;

said removing means comprising a hinged portion just above the water line, said hinged portion adapted to permit the folding of said self-steering system at said hinged portion.

10. A self-steering system for a boat, comprising:

a wind vane mounted on said boat;

said wind vane adapted to undergo angular displacemerits;

said wind vane having a hollow symmetrical wedge shape;

said wind vane having a frame with a plurality of normally hidden permanent support arms that can be exposed to a stiff wind by removing the cover from said frame;

a rudder comprising a body portion pivotally mounted with respect to said boat;

said rudder further comprising a servo-tab pivotally mounted on said body portion of said rudder;

said servo-tab having a substantially wedge shaped cross-section, with the trailing edge of said servotab formed into an anti-vortexing configuration;

transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder for causing said servo-tab to undergo a corresponding angular displacement;

means for causing the underwater water-flow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat;

whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane;

said transmission means further comprising a pulley adapted to pivot with said wind vane;

said transmission means further comprising a belt adapted to engage said pulley;

said transmission means further comprising clutch means for engaging and disengaging said pulley/- belt arrangement.

11. The combination of claim 10 including gimballing means for causing said wind-vane to maintain a substantially vertical orientation;

said gimballing means comprising a weighted pendulous shaft adapted to maintain a substantially vertical orientation;

said wind-vane being adapted to remain in alignment with said pendulous shaft. 

1. A self-steering system for a boat, comprising; a hollow symmetrical wedge shaped wind vane mounted on said boat, said wind vane adapted to undergo angular displacements; a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder; transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab; clutch means for engaging and disengaging said wind vane and said rudder; means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat; whereby the power for pivoting said body portion to said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.
 2. The combination of claim 1 wherein said servo-tab and said body portion of said rudder are positioned with their upper ends slightly above the water level.
 3. The combination of claim 1 wherein said transmission means comprises a first clutch element adapted to pivot with said wind-vane, and further comprises a second clutch element adapted to engage said servo-tab.
 4. A self-steering system for a boat, comprising: a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements; said wind vane being of a hollow symmetrical wedge shape, having a frame and cover therefor, said frame having a plurality of normally hidden permanent arms that can be exposed to a stiff wind by removing said cover from said frame; a rudder comprising a body portion pivotAlly mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder; transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab; means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat; whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.
 5. A self-steering system for a boat, comprising: a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements; a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted at its leading edge to said body portion of said rudder; said servo-tab having a substantially wedge shaped cross-section so as to increase in width from its leading to its trailing edge; transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab; means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat; whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.
 6. A self-steering system for a boat, comprising: a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements; a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder; transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab; said transmission means comprising a pulley adapted to pivot with said wind vane, and further comprising a belt adapted to engage said pulley; said transmission means further comprising clutch means for engaging and disengaging said pulley/belt arrangement; means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat; whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.
 7. A self-steering system for a boat comprising: a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements; gimballing means for causing said wind vane to maintain a substantially vertical orientation; a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted at its leading edge to said body portion of said rudder; said servo-tab having a substantially wedge shaped cross-section so as to increase in width from its leading to its trailing edge; transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab; means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudDer relative to said boat; whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane.
 8. The combination of claim 7 wherein said gimballing means comprises a weighted pendulous shaft adapted to maintain a substantially vertical orientation, and said wind-vane is adapted to remain in alignment with said pendulous shaft.
 9. A self-steering system for a boat, comprising: a wind vane mounted on said boat, said wind vane adapted to undergo angular displacements; a rudder comprising a body portion pivotally mounted with respect to said boat, and further comprising a servo-tab pivotally mounted on said body portion of said rudder; transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder to produce a corresponding angular displacement of said servo-tab; means for causing the underwater waterflow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat; whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane; means for removing the normally submerged portion of said rudder from the water; said removing means comprising a hinged portion just above the water line, said hinged portion adapted to permit the folding of said self-steering system at said hinged portion.
 10. A self-steering system for a boat, comprising: a wind vane mounted on said boat; said wind vane adapted to undergo angular displacements; said wind vane having a hollow symmetrical wedge shape; said wind vane having a frame with a plurality of normally hidden permanent support arms that can be exposed to a stiff wind by removing the cover from said frame; a rudder comprising a body portion pivotally mounted with respect to said boat; said rudder further comprising a servo-tab pivotally mounted on said body portion of said rudder; said servo-tab having a substantially wedge shaped cross-section, with the trailing edge of said servo-tab formed into an anti-vortexing configuration; transmission means for transmitting said angular displacement of said wind vane to said servo-tab of said rudder for causing said servo-tab to undergo a corresponding angular displacement; means for causing the underwater water-flow pattern to produce an increased water pressure on the exposed surface of said angularly displaced servo-tab, and to thus cause the increased water pressure to pivot said body portion of said rudder relative to said boat; whereby the power for pivoting said body portion of said rudder is obtained from the underwater waterflow pattern, and not from said wind powered wind vane; said transmission means futher comprising a pulley adapted to pivot with said wind vane; said transmission means further comprising a belt adapted to engage said pulley; said transmission means further comprising clutch means for engaging and disengaging said pulley/belt arrangement.
 11. The combination of claim 10 including gimballing means for causing said wind-vane to maintain a substantially vertical orientation; said gimballing means comprising a weighted pendulous shaft adapted to maintain a substantially vertical orientation; said wind-vane being adapted to remain in alignment with said pendulous shaft. 